Photocatalytic Degradation of the Pharmaceutical Pollutant Tetracycline Using a Solar-Activated Nanocatalyst

Abstract

The presence of pharmaceutical contaminants in aquatic environments has raised significant environmental concerns, necessitating the development of efficient and sustainable treatment technologies. In this study, a solar-activated nanocomposite photocatalyst composed of ZnFe2O4 and Co3O4 nanoparticles immobilized on a bentonite support was synthesized and applied for the photocatalytic degradation of tetracycline as a model pharmaceutical pollutant. The bentonite matrix provided a high surface area and improved dispersion and stability of the active metal oxide nanoparticles. The photocatalytic performance of the ZnFe2O4–bentonite–Co3O4 (ZBC) nanocatalyst was evaluated under solar irradiation, and the effects of solution pH and catalyst dosage on tetracycline removal were systematically investigated. The results demonstrated that photocatalytic efficiency strongly depended on operational conditions. Under optimal conditions (pH = 3 and catalyst dosage of 0.03 g), approximately 69% of tetracycline was degraded within 3 h of solar exposure. The enhanced photocatalytic activity can be attributed to the synergistic effect between ZnFe2O4 and Co3O4, as well as the adsorption capacity and structural support provided by bentonite. These findings indicate that the synthesized ZBC nanocomposite is a promising and environmentally friendly photocatalyst for the solar-driven removal of pharmaceutical pollutants from water.